I beat the three headed panzer 10 times and did not get the medal for the next. Is it a random drop?

They're achievement loots @ 10 wins so you should only get it once. Double check its not in your inventory & your achievements.

Okay thank you. I guess I did it some other year and never activated it. Not sure but I do not have the medal and my achievement list does not show the 3 headed, only the 5 headed so I guess I lost the medal somehow. I am sure I would not have sold it though. I guess I am going to have to drop 40 mill on a medal if I want to advance to the next.